Jiann-Shing Lih

EXPERIMENTAL SUPPRESSION OF CHAOS IN A MODULATED MULTIMODE LASER

Suppressing chaotic behavior by addition of a weak second periodic perturbation signal, which is nearly resonant to a subharmonic of the fundamental system frequency, is observed in a modulated microchip LiNdP(4)O(12) multimode laser by a highly sensitive self-mixing modulation technique. The stabilization of the unstable period-2 orbit embedded in a chaotic attractor is demonstrated in a wide parameter region. The chaos-suppressing experiments are well reproduced by simulations of globally coupled modulated Tang-Statz-deMars [J. Appl. Phys. 34 8289 (1963)] multimode laser equations, including a spatial hole-burning effect.

Electromagnetic resonance in deformed split ring resonators of left-handed meta-materials

Recently, structures called deformed split ring resonators have been proposed to achieve the smallest volume of a unit cell, while retaining negative permeability. With a combination of wire structures, the characteristics of a negative index of refraction, or left-handed meta-materials, can be seen from the transmission spectrum. This electromagnetic resonance, including its orientation tolerance and angular dependence on the incident beam, is explored in detail in the microwave range.

Transmission Characteristics of Deformed Split-Ring Resonators

A metallic-microstructure composite, which is comprised of deformed-split-ring resonators (DSRRs) and wires, is shown to preserve the transmission characteristics of a left-handed metamaterial, implying the simultaneously negative values of effective permeability and permittivity, as well as a wider bandwidth of resonance. Furthermore, the DSRR is so designed that it minimizes the size of the unit cell for fabrication, which is favorable for the implementation of left-handed metamaterial in near infrared region.

Enhanced transmission through a sub-wavelength aperture in a metal foil by using a complementary patch: Microwave optics analog

Experimental results show that a complementary metal patch located in front of a sub-wavelength aperture in a metal foil remarkably enhanced the microwave transmission. Without periodic pattern grooved over the sample, the transmission enhancement is not due to the conventional grating coupling of surface plasmons, but to peculiar resonating between the complementary patch and the aperture-excavated metal foil.

RECOGNIZING HIDDEN FREQUENCIES IN A CHAOTIC TIME SERIES

Abstract Using the method of phase space reconstruction (PSR), it is possible to detect dynamically connected hidden frequency components in a chaotic time series. Here, we suggest to use the method of singular value decomposition (SVD) in tandem with the PSR. With this new scheme, the procedure to search for the hidden frequencies can be simplified substantially and the search efficiency can be improved greatly. We use the Lorenz model, the Rossler model, and the hyperchaotic Rossler model to illustrate how this PSR/SVD scheme works.